As an example topic, here's how Social Media could be studied using each of the Four Lenses.
The History lens examines social media as a recent phenomenon in a longer period of time where other types of media have been dominant. It prompts questions about what gave rise to social media, how it has evolved, and how it compares and contrasts with newspapers, radio, television, etc., as media forms that have been around longer.
The Humanities lens looks at social media as an art form, its elements of visual design and use of language, memes, humor, etc., as an expression of social and cultural traits of the times which produced it.
The Social Sciences lens asks questions about social media's impact on society and culture, what drives its popularity and influence as a new form of mass communication, how it affects human behavior, how people use it to bond, share experiences, and make choices about how to spend money, who to vote for, where to live, etc.
The Natural Sciences lens investigates the effects of "screen time" on the human brain, what chemical changes might occur that influence emotions or cognition, or how social media might be used to control wildfires or monitor ocean pollution as an instrument of science.